That house next door is really hanging on! Maybe it's time to go over and smudge it or something and release it to the universe. This is a really good argument against moving in next to a family member, as you end up with kind of a compound thing going on, and it gets really complicated to sell one of the houses.
Gosh I am so sorry this is turning out to be so involved. Sending good thoughts your way to get the house sold and the situation straightened out. So, so sorry you are having this stress right now.
Am sending good wishes to you that this mess gets straightened out this week!